MANUFACTURING OF AN OXYGEN PLSMA TRI-ARC FURNACE FOR OXIDE CERAMICS

1993 Fiscal Year Final Research Report Summary

• Project/Area Number: 04555156
• Research Category: Grant-in-Aid for Developmental Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: Physical properties of metals
• Research Institution: TOTTORI UNIVERSITY
• Principal Investigator: HAYAKAWA Motozo TOTTORI UNIV., FACULTY OF ENGINEERING,PROFESSOR, 工学部, 教授 (60093621)
• Co-Investigator(Kenkyū-buntansha): OKAMOTO Hisaki TOTTORI UNIV., FACULTY OF ENGINEERING,ASSOCIATE PROFESSOR, 工学部, 助教授 (30029889) ; OKA Muneo TOTTORI UNIV., FACULTY OF ENGINEERING,PROFESSOR, 工学部, 教授 (60029866)
• Project Period (FY): 1992 – 1993
• Keywords: Oxygen Plasma-Arc Furnace / Melting of Ceramics / Dendritic Structure / Homogenization / Oxidation-Reduction / Zirconia / Zirconia-Yttria / Zirconia-Ceria

Research Abstract

1. Three sets of oxygen plasma torches and power units were purchased and a control unit which enables instantaneous transition from a transfer mode to a nontrnasfer mode of a torch operation were manufactured.
2. A simple furnace with fixed torches were manufactured for preliminary melting experiments through which suitable conditions for melting were sought and data necessary for manufacturing a final furnace.
3. Through the melting experiments of zirconia alloys using the preliminary furnace, the following results were obtained : (1) Yttria doped zirconia could be melted without reduction under the oxygen plasma arc. (2) Although ceria doped zirconia resulted in dendrite structure through the solidification, this could be removed by homogenizing heating just below the melting temperature. (3) Because of the thin arc of the oxygen plasma, heating of a spcimen above 10mm size could not be heated uniformly.
4. Based on these data, a furnace with a rotating hearth with up-down motion was manufactured.